1. Field of the Invention
This invention is related to a technique of reducing color noise in an image captured by a digital camera.
2. Description of the Related Art
A Charge Coupled Device (CCD) in a digital camera often generates color noise in an image captured with the CCD under dark conditions because of dark current noise and other inherent noises of the CCD. The color noise appears as a significant change of pixels and reduces the quality of the image.
One method for reducing such color noise is to average the color components of pixels adjacent to a given pixel to be corrected. See, for example, JP 2001-175843. However, color noise often spreads to the adjacent pixels. Thus, according to the conventional technique for correcting color noise disclosed in JP 2001-175843, colors of pixels adjacent to a given pixel, including pixels which are affected by color noise, are averaged. As a result, this conventional method cannot effectively reduce color noise, and rather causes the image to be less sharp.